:: deftheorem Def3 defines central_symmetric MATRIX17:def 3 :
for K being Field
for n being Nat
for M being Matrix of n,K holds
( M is central_symmetric iff for i, j, k, l being Nat st [i,j] in Indices M & k = (n + 1) - i & l = (n + 1) - j holds
M * (i,j) = M * (k,l) );